Genetic Variant GAA:p.Asn87GlnfsTer9 (chr17-80104837-T-TC) – ACMG Classification: Pathogenic (13 pts)

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PM2_SupportingPM3PP4_ModeratePVS1

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.258dup (p.Asn87GlnfsTer9) variant in GAA is a frameshift variant predicted to cause a premature stop codon in biologically-relevant-exon 2/20, leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). At least 10 patients with this variant and reported to have Pompe disease have been reported. This includes two patients with documented laboratory values showing GAA deficiency meeting the ClinGen LSD VCEP’s specifications for PP4_Moderate; one of them on enzyme replacement therapy (PMID 21484825, 31467850), a further 7, at least, patients on enzyme replacement therapy, without documented values for GAA activity, meeting specifications for PP4 (PMID 26873529, 31086307, 31392188, 31676142, 32248831), and additional patients with insufficient details to meet the requirements for PP4 (PMID 10206684, 16917947, 29961517, 30564623). At least 7 patients are compound heterozygous for the variant and a pathogenic variant, c.-32-13T>G, in GAA (PM3). Another two patients are compound heterozygous for the variant and either c.1195-8G>A (PMID 21484825) or c.1115A>T (p.His372Leu) (PMID 31467850). The in trans data from both of these patients will be used in the assessment of the other variant and is, therefore, not included here in order to avoid circular logic. The variant is absent in gnomAD v2.1.1 (PM2_Supporting). There is a ClinVar entry for this variant (Variation ID: 282842, 2 star review status) with five submitters classifying the variant as pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. GAA-specific GAA criteria met, as specified by the ClinGen LSD VCEP (Specification Version 2.0): PVS1, PM3, PP4_Moderate, PM2_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA8814826/MONDO:0009290/010

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000054 ( 0 hom. )

Consequence

GAA
NM_000152.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic reviewed by expert panel P:14

Conservation

PhyloP100: -0.512

Publications

6 publications found

Variant links:

Genes affected

GAA (HGNC:4065): (alpha glucosidase) This gene encodes lysosomal alpha-glucosidase, which is essential for the degradation of glycogen to glucose in lysosomes. The encoded preproprotein is proteolytically processed to generate multiple intermediate forms and the mature form of the enzyme. Defects in this gene are the cause of glycogen storage disease II, also known as Pompe's disease, which is an autosomal recessive disorder with a broad clinical spectrum. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]

GAA Gene-Disease associations (from GenCC):

glycogen storage disease II
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), PanelApp Australia, ClinGen, G2P
glycogen storage disease due to acid maltase deficiency, infantile onset
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
glycogen storage disease due to acid maltase deficiency, late-onset
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

GAA links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 13 ACMG points.

PVS1

For more information check the summary or visit ClinGen Evidence Repository.

PM2

For more information check the summary or visit ClinGen Evidence Repository.

PM3

For more information check the summary or visit ClinGen Evidence Repository.

PP4

For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000152.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
GAA	NM_000152.5	MANE Select	c.258dupC	p.Asn87GlnfsTer9	frameshift	Exon 2 of 20	NP_000143.2
GAA	NM_001079803.3		c.258dupC	p.Asn87GlnfsTer9	frameshift	Exon 3 of 21	NP_001073271.1
GAA	NM_001079804.3		c.258dupC	p.Asn87GlnfsTer9	frameshift	Exon 2 of 20	NP_001073272.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
GAA	ENST00000302262.8	TSL:1 MANE Select	c.258dupC	p.Asn87GlnfsTer9	frameshift	Exon 2 of 20	ENSP00000305692.3
GAA	ENST00000390015.7	TSL:1	c.258dupC	p.Asn87GlnfsTer9	frameshift	Exon 3 of 21	ENSP00000374665.3
GAA	ENST00000933406.1		c.258dupC	p.Asn87GlnfsTer9	frameshift	Exon 2 of 20	ENSP00000603465.1

Frequencies

GnomAD3 genomes

AF:

0.0000330

AC:

AN:

151632

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000243

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000589

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000122

AC:

AN:

246016

AF XY:

0.0000149

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000291

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000181

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000541

AC:

AN:

1459916

Hom.:

Cov.:

AF XY:

0.0000468

AC XY:

AN XY:

726320

show subpopulations

African (AFR)

AF:

0.0000598

AC:

AN:

33464

American (AMR)

AF:

0.0000224

AC:

AN:

44680

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26116

East Asian (EAS)

AF:

0.00

AC:

AN:

39656

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86194

European-Finnish (FIN)

AF:

0.00

AC:

AN:

51928

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000639

AC:

AN:

1111776

Other (OTH)

AF:

0.0000663

AC:

AN:

60336

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.472

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000330

AC:

AN:

151632

Hom.:

Cov.:

AF XY:

0.0000270

AC XY:

AN XY:

74006

show subpopulations

African (AFR)

AF:

0.0000243

AC:

AN:

41232

American (AMR)

AF:

0.00

AC:

AN:

15248

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3464

East Asian (EAS)

AF:

0.00

AC:

AN:

5160

South Asian (SAS)

AF:

0.00

AC:

AN:

4784

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10542

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000589

AC:

AN:

67894

Other (OTH)

AF:

0.00

AC:

AN:

2080

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.505

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000189

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

ClinVar submissions as Germline

Significance:Pathogenic

Revision:reviewed by expert panel

View on ClinVar

Pathogenic

VUS

Benign

Condition

Glycogen storage disease, type II (7)

not provided (6)

GAA-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

PhyloP100

-0.51

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

17-80104837-TC-TCC

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over